SU555179A1 - Device for measuring the weight of the tape - Google Patents

Description

The invention relates to automatic devices for controlling the weight of the tape in the textile industry and can be used in automatic weight control systems for the tape.

A device for measuring the weight of a tape by a photoelectric method is known, which comprises a light source, an optical system and a photodetector connected to the input of an amplifier with a recording device.

The disadvantage of such a device is the dependence of the measurement results on the color of the dyed fiber.

It is also known to have a photoelectric device for measuring and adjusting the ribbon spread, where the radiant flux from the incandescent lamp passes through the optical system containing infrared filters and is sensed by a photo receiver connected to the input of the regulator with a recording device.

However, in the known device, the transmission coefficient of the measuring path is highly dependent on external factors due to the use of direct current amplifiers in the device, since the radiation flux is not modulated.

In order to increase the weight accuracy of the tape, the proposed device contains a comparison unit, an optical modulator and two synchronous detectors, the signal input of one of which is electrically connected to the amplifier, and one of its outputs is connected to the control input of the second synchronous detector, the output of which is through the comparison unit electrically connected to the input of the power supply unit, the signal input of the second synchronous detector electrically connected to the output of the optical modulator; the emitter and photodetector are optically coupled with a branched light guide, one of the branches of which is located in the zone of the forming funnel of the tape machine, and an optical modulator is placed in the path of the second branch, while the emitter is made in the form of a semiconductor modulated infrared flux.

FIG. 1 shows the weight sensor; in fig. 2 is given a block diagram of the proposed device. The tape weight sensor (Fig. 1) consists of forming funnel 1, which is designed to form tape 2 in work zone 3. Two fiber components 4 and 5 are the optical system of the sensor, the fiber component 4 consisting of two light guides 6 and 7, and Fiber part 5 consists of optical fibers 8 and 9. The optical system of the sensor is made of special glass fibers arranged in bunches and glued at the ends. The radiant flux of the radiation source of the LED 10 is brought to the end of the fiber part 4. The light guide 6 is intended to transmit the radiant flux of the LED 10 to the working area 3, and the light guide 7 to the optical signal of the stabilization signal, the light guides 8 and 9 to receive the radiant flux. By changing the order of the glass fibers of the light guide 6, a circular-rectangular optical transducer is made, i.e. the common end of the fiber part 4 has a cross-section, and the end of the light guide 6 has a narrow rectangular slit shape. Fiber part 5 differs from fiber part 4 only in geometrical dimensions. A semiconductor injection LED 10 is used as the source of the radiant flux in the sensor, giving a monochromatic radiant flux in the near infrared region of the spectrum. It is fixed to the circular pre-polished end of the fiber part 4, the light guide 6 is fixed in the working zone 3, where the torus of the light guide 8 is also installed. A photodetector 11, a photodiode, is attached to the end of the fiber part 5. To obtain an optical stabilization signal, optical fibers 7 and 9 are used in the sensor, as well as a modulator 12, which is an amplitude modulator of the optical signal. The device (Fig. 2) contains a power supply unit 13 connected to the sensor 14, which consists of an LED 10, a funnel 1 and a photodetector 11 electrically connected to the input of the recording device 15. The output of the recording device 15 is connected to the input of the stabilization device 16 transfer measuring track. The power supply unit 13 is discharged from a sinusoidal oscillator 17, which is connected via a switch 18 to an LED 10. A photodetector 11 is connected to a recording device 15 containing an alternating voltage amplifier 19, the output of which is electrically connected to the signal, a synchronous detector input 20. Control input A synchronous detector 2 O is connected to the output of the generator 17. One of the outputs, synchronously with the detector 20, is electrically connected to a registering device. 21, and the second with the control input of the synchronous detector 22 of the stabilization device 16. The signal input of the synchronous detector 22 is connected to the output of the modulator 12, and the output of the synchronous detector 22 is connected to the input of the comparison circuit 23 of the stabilization signal and the reference voltage It is the input of a switch 18, which serves to control the current of the LED 10. The device operates as follows. The self-oscillator 17 controls the operation of the switch 18, the LED 10 in series with it. If the output of the comparison circuit 23 of the stabilization signal and the reference voltage of the Is51 51 control signal is zero, then the switch 18 and the LED 10 will flow a pulse current whose value is determined by the initial the parameters of the key 18. Thus, the radiant flux Fo of the LED 10 will be modulated by the frequency P of the oscillator 17. The tape 2 is charged into the shaping funnel 1 and introduced into the working zone 3 of the sensor (Fig. 1). The radiant flux Fo of the LED 10 through the light guide 6 enters the working zone 3, then passes through the tape 2 and the receiving light guide 8 enters the photodetector 11, at the output of which alternating voltage U (P) -f ((5) appears, where the F-radiant flux arriving at the photo-receiver 11. The radiant flux F0 also enters through the light guide 7 to the modulator 12, after which it is modulated by a frequency FJ different from F (F-o, IF). The twice-modulated radiant flux arrives at the photodetector 11, at the output of which alternating voltage 1/2 (F,) (Fo) appears. Thus, the input of amplifier 19 (Fig. 2) receives a total signal And (p, with the voltage U (T) carrying information about the degree of absorption of the radiant flux P0 by tape 2 in the working zone 3, and Uj (Pa) carries information about the total the radiant flux F0 of the LED Y. The total electrical signal tJ amplified by amplifier 19 is fed to the signal input of the synchronous detector 20, the keys of which are controlled by the frequency F., the oscillator 17. A constant voltage KjQ appears at the output of the synchronous detector 2 O (P. ) and variable component ® K.j - transfer coefficient the amplifier 19 and the synchronous detector 20, the DC voltage U is fed to the registering device 21. The alternating voltage C is fed to the signal input of the synchronous detector 22, the keys of which are controlled by the frequency Fp of the modulator 12. At the output of the synchronous detector 22 is a constant voltage and, where K is the transmission coefficient of the synchronous detector 22. The voltage E2 is a signal to stabilize the transfer coefficient of the measuring waste. If the voltage E and the reference voltage Uconst are equal, then at the output of the comparison circuit 23 the control signal is Eupr. will be zero. The deviation of the parameters of any element of the measuring path, caused by aging of the elements, a change in the ambient temperature, a change in the supply voltage, etc., will lead to a change in the stabilization signal E2 + E. At the output of the comparison circuit 23, the signal Eupr O, which affects the key 18 , will change the current of the diode 10 so that the stabilization signal returns to its original value I. Thus, the transmission coefficient of the measuring path is maintained with high accuracy by feedback on the signal stable. lization. The introduction of a signal to stabilize the transmission coefficient of the measuring path and fiber optics allows for an order of magnitude increase in the accuracy of measuring the weight of the tape. The use of an infrared monochromatic, modulated source of radiant flux-injection light code makes it possible to simplify and reduce the optical system of the sensor and use it to measure the weight of the tape, regardless of its color and type of fiber. Such a sensor can also be used for

Claims (3)

FIG. 1 measure the thickness of a variety of translucent materials, such as paper, plastic film, nonwoven and durable textile materials. Claim 1. A device for measuring the weight of a tape on tape machines, comprising a forming funnel, a radiator with a power supply, an optical system, a photodetector connected to the input of the amplifier and a recording unit, characterized in that, in order to increase the accuracy of the weight of the tape, it has a block comparison, an optical modulator and two synchronous detectors, the signal input of one of which is electrically connected to the amplifier, and one of its outputs is connected to the control input of the second synchronous detector, the output of which through the block compared; 1 is electrically connected to the input of the power unit, wherein the signal input of the second synchronous detector connected to an output of the optical modulator. 2. The device according to claim 1, characterized by the fact that the emitter and photodetector are optically coupled to a branched light guide, one of the branches of which is located in the zone of constriction of the forming funnel of the ribbon mass, and in the path of the second branch an optical modulator is placed . 3. The device according to claim 1, characterized by the fact that the emitter is made in the form of a semiconductor source of modulated infrared flux. 13 L , 11 G / $ / and ten IS 17 and 1 g 20 13 and. (Jcons-t 2 i g J Ф14г.2.